Kopernio (previously Canary Haz ( http://kopernio.com)Note this is a .com extension. This new company has been founded just 8 months ago. The Kopernio extension was released just in March 2017. Currently the Kopernio button is in alpha-testing and so far it seems free. The previous name appeared to be a tribute to the #ICANHAZPDF movement (requesting pdf's via Twitter with this hashtag).Kopernio extends the reach (and functionality) of your library linkresolver to the browser.It goes beyond the reach of the traditional library linkresolvers which show you if you are entitled to get the full-text based on checking your subscriptions database. It tries to solve the problem of the linkresolvers, early-online issues, publishers holdings- and access registrations. There are always discrepancies, bills not paid, backlog of mutations, titles changes etc etc. Kopernio does not only shows users the publications they can immediately open as pdf based on library subscriptions, but also other free versions that are out there on the Web. If your library holdings say NO, but the publisher left it open, you get the pdf. There is no doubt. Either you get it or not.RegistrationYou HAVE to create an account. If you register with your institutional /corporate email, it is then connected to the proxy settings of that particular library. When opening the webpage of a journal article or institutional respositories, e-print-servers etc) a #kopernio bar indicates (just like the Unpaywall tab) immediately IF a pdf has been found.

Off-campusThe first time using Kopernio off-campus, your proxy login details are stored encrypted IN the plugin, and are never shared with Kopernio servers or others.If your library proxy settings have not yet been added to the Haz-bar give them a shout on Twitter , on Linkedin or Facebook. Their response so far has been excellent. They even have added the Groningen institutional repository as the world's first repository activated for Kopernio, on my request! So, every page on that repository, containing a DOI, WILL be "hazzed". I am coining the verb "hazzing" for showing available versions of scientific publications or data (free, open access or licensed) in a browser! ;-) It's is therefore not only using institutional repositories as a source to harvest pdf's, but also as a target to show the Kopernio Get PDF button/bar.In Search results vs article detailed view (PubMed and Google Scholar)The Kopernio button appears also in PubMed search results to offer direct access to the pdf, instead on the article view level. This is also activated for Google Scholar search result page, which makes it possible to do pratical comparison between the coverage of Google Scholar itself, Kopernio ánd the Library linkresolver showing up as Library Links in Scholar.

You can then click GET PDF. Your Kopernio registration then allows you to choose to either add it to your LOCKER, Bookmark it to read the article later, or download the pdf.Clicking on the #kopernio logo in the upper left corner, takes you to the LOCKER with your saved articles/bookmarks. There is a build-in viewer to read your pdfs. You can download the citation to .bib currently.How does it work?With thanks to Ben Kaube, one of the founders of Kopernio (previously Canary Haz), I can now write that Kopernio does quite a lot of things in the background, Parallel searches for the best PDF version are made currently:

The following sources are considered:

- Links to PDFs on the page (e.g. as you might find on an OA article page)

- "Deep links" via institutional libraries. This requires authentication against the library the first time Kopernio is used off-campus.

- Kopernio's index of open PDFs articles

- Cached Google scholar results

- Your Kopernio PDF search history known as your "locker"

They are working with a (fast growing) whitelist of websites right now and they are adding more institutional repositories to these lists too.

Depending on which (if any) of the above returns positive, the bar may take between 1 and 20 seconds to complete its search (Kopernio claims the average is around 3 seconds).When making a head to head comparison with Unpaywall it's worth considering that the Kopernio link goes straight to the PDF while Unpaywall may take you to a sequence of interstitial pages first.Kopernio DID find a PDf version which seem to come directly from the publisher, because it is using my library proxy settings! So, I login once, and after that I don't need to do that at all anymore!

Google scholar buttonFinds full-text versions on the web. You can connect Google Scholar to your library's linkresolver (OCLC in my case) in Settings; Library Links; find your library and SAVE.In this case it finds the PDF based on your library subscription AND a free version of Ualberta.ca. I have no idea why this UAlberta.ca version is available for all, but it does not look to be open access or a final author's version.

Unpaywall (http://unpaywall.org) This add-on shows immediately if there is a free version without even having to click. It shows up as a coloured button on the right side in the browser screen.

See a green tab when they find fulltext from an institutional repository or preprint server, and a gold tab when we find journal-hosted content with an Open license. When we find journal-hosted fulltext with no license you'll get a blue tab. And grey means NO full-text available. You can activate the coulour-coded tab in Settings. Another setting can hide content from less trusted sources. You won't see fulltext from ResearchGate, Academia.edu, researcher homepages, and some IRs. This option decreases coverage by about 20%.Clicking the coloured tab opens up the free version from UAlberta.ca immediately.

Open Access Button (https://openaccessbutton.org/) You have to click the button in the Toolbar to get it working.In this case -after searching for a few seconds- it does NOT show me any available version, but the Request article or data option. This feature will eventually send a request to the AUTHOR for a copy.

This bookmarklet in your browser forces you to go via the Library proxy-login, wherever you are on the web. It takes you from the PAYwall to the PDF, if the library has access to the full-text based on their subscriptions. You just have to click on the CONNECT in the bookmark-bar. The choice to save your proxy login details in your browser is yours, but it can be very useful.I am working on a screencast to demonstrate all these extensions. "to be continued' ...